Soybean growers heading into the 2013 planting season might find that many soybean seeds are larger than normal - a lingering impact from the 2012 drought, says an expert with Ohio State University's College of Food, Agricultural, and Environmental Sciences (CFAES).
On average, 2,500 individual soybean seeds constitute a pound, said Laura Lindsey, a soybean and small grain specialist with the college's outreach arm, Ohio State University Extension. But considering that dry conditions during seed fill followed by August and September rains can result in larger than normal seeds, growers could find instances where 1,700 seeds constitute a pound, she said.
Last year's drought conditions plus late-season rains expedited the growth of soybean plants, which has caused fewer seed pods and larger seeds for growers to plant this year, Lindsey said.
"Because of last year's drought, which is when the seeds were grown out that will be used to plant this year, many growers are wondering what they need to consider going into the 2013 planting season," she said. "The question has come up at several Extension meetings across the state, as growers worry about how last year's drought could impact them this year."
Growers should check soybean seed size before planting this year and contact their equipment dealer or check their operator's manual to adjust for seed size if planting abnormally large or small seed, Lindsey said. And because drought can have a negative impact on seed quality, growers should check germination results of their seeds.
"Germination is considered good if it is approximately 95 percent," she said. "If germination is less than 90 percent, consider increasing the seeding rate.
"To adjust the seeding rate because of low reported germination test results, divide 0.9 by the germination rating on the seed tag. Then multiply that number by the normal seeding rate."
But, Lindsey said, seed companies typically don't sell low-quality seeds.
"I'm not too worried about the quality," she said. "Most seed companies check seed quality several times, including when they get it, when they apply seed treatments and anytime they handle the seed."
Growers should also avoid field operations when soil conditions are too wet, Lindsey said. Some areas of Ohio experienced soil compaction after harvesting in too wet soil conditions, she said.
"Soybean germination and emergence were negatively affected by compaction areas from the 2011 harvest," Lindsey said. "So if possible, avoid field operations when soil conditions are too wet because you may see uneven soybean emergence as a result."
Indiana and all but northwest Ohio have returned to normal soil moisture conditions, according to the April 16 U.S. Drought Monitor.